What made the LTFT's go positive...
 

Ok, guys I have been chasing knock here lately. So I did top engine cleaner, charged oil, changed plugs, and added 100 octane. So my question is which made the LTFT's go positive? The octane or the plugs.. They were in the -4 to -6 range. Now they are 2 to 3 positive. I need advice before I mess with HP tuners if its just the octane I'll leave it for a while, if its the plugs I'll change it now and get back out there.

Thanks as always.

Z

In my case it was a dirty MAF sensor. Can of Radio Shack electronics cleaner did the trick.

The two test were only about an hour and a half apart. I just realized what happened. I opened the gap on the spark plugs. So I guess I'm gonna go tune injector flow rate.